import { useEffect, useMemo, useState } from "react";
import { selectedCharacter, useShellStore } from "../app/shellStore";
import { useDungeonRaceStore, type RacePool } from "../app/dungeonRaceStore";
import { loadDungeonQueuePolicy, useDungeonQueuePolicyStore } from "../app/dungeonQueuePolicyStore";
import { requestOnlineJson } from "../app/onlineAccountClient";
import { type RaceBotSource, type RaceBotTier } from "../app/dungeonRaceBot";
import { dungeonsByCategory, randomizedBiteSizedDungeons } from "../game/dungeonCatalog";
import { dungeonEnabledForQueue } from "../game/dungeonQueuePolicy";
import { formatDungeonDuration } from "../game/dungeonRunTypes";
import { dungeonRaceAffix } from "../game/dungeonRaceAffixes";
import { dungeonLeaderboardCatalog as leaderboardCatalog } from "../game/dungeonLeaderboardCatalog";
import { partyRolesForClass, PARTY_ROLE_LABELS, type PartyRole } from "../game/partyStore";
import { specializationById } from "../game/specializationCatalog";
import { BrandMark, FrontSurface } from "./FrontSurface";
import "./dungeonRace.css";
import { BiteSizedBoardFilters, useBiteSizedBoardSelection } from "./BiteSizedBoardFilters";

interface BoardEntry { readonly accountId: string; readonly username: string; readonly rank: number;
  readonly wins?: number; readonly losses?: number; readonly durationMs?: number;
  readonly affixIds?: readonly string[] }
interface BoardResponse { readonly entries: readonly BoardEntry[]; readonly total: number }

export function DungeonRaceScreen({ onClose }: { readonly onClose: () => void }) {
  const character = useShellStore((state) => state.activeCharacter) ?? useShellStore(selectedCharacter);
  const session = useShellStore((state) => state.session);
  const race = useDungeonRaceStore();
  const policy = useDungeonQueuePolicyStore((state) => state.config);
  const refreshPolicy = useDungeonQueuePolicyStore((state) => state.refresh);
  const [pool, setPool] = useState<RacePool>("authored");
  const [dungeonId, setDungeonId] = useState("");
  const [practice, setPractice] = useState(!session?.accessToken);
  const [tier, setTier] = useState<RaceBotTier>("regular");
  const [source, setSource] = useState<RaceBotSource>("wow");
  const [role, setRole] = useState<PartyRole | null>(null);
  const [period, setPeriod] = useState<"30d" | "all">("30d");
  const [boardScope, setBoardScope] = useState<"overall" | "dungeon">("overall");
  const [boardView, setBoardView] = useState<"wins" | "times">("wins");
  const [boardBossId, setBoardBossId] = useState("");
  const [board, setBoard] = useState<BoardResponse | null>(null);
  const [boardError, setBoardError] = useState("");
  useEffect(() => { void refreshPolicy(session); }, [refreshPolicy, session]);
  const allEntries = useMemo(() => (pool === "randomized" ? randomizedBiteSizedDungeons()
    : dungeonsByCategory("bite-sized")).filter((entry) => entry.available && dungeonEnabledForQueue(policy, entry)),
  [pool, policy]);
  const boardDungeonId = dungeonId || allEntries[0]?.id || "";
  const boardDungeon = leaderboardCatalog.dungeons.find((entry) => entry.id === boardDungeonId);
  const bossOptions = boardDungeon?.difficulties.find((entry) => entry.id === boardDungeon.defaultDifficultyId)
    ?.finalBossIds?.map((id) => boardDungeon.bosses.find((boss) => boss.id === id)!) ?? [];
  const selectedBoardBossId = bossOptions.find((boss) => boss.id === boardBossId)?.id ?? bossOptions[0]?.id;
  const spotBoard = useBiteSizedBoardSelection(boardDungeonId);
  useEffect(() => {
    const controller = new AbortController();
    const query = new URLSearchParams({ view: boardScope === "overall" ? "wins" : boardView,
      period, ...(boardScope === "dungeon" && boardDungeonId ? { dungeon: boardDungeonId,
        ...(selectedBoardBossId ? { boss: selectedBoardBossId } : {}),
        ...(boardView === "times" && spotBoard.spotId ? { spot: spotBoard.spotId, spotRevision: String(spotBoard.spotRevision) } : {}) } : {}) });
    if (boardScope === "dungeon" && !boardDungeonId) { setBoard(null); return; }
    void requestOnlineJson<BoardResponse>(`/api/dungeon-races/leaderboard?${query}`, { signal: controller.signal })
      .then((value) => { setBoard(value); setBoardError(""); })
      .catch((error: unknown) => { if (!controller.signal.aborted) { setBoard(null);
        setBoardError(error instanceof Error ? error.message : "Leaderboard unavailable."); } });
    return () => controller.abort();
  }, [boardDungeonId, boardScope, boardView, period, selectedBoardBossId, spotBoard.spotId, spotBoard.spotRevision]);
  const specialization = specializationById(character?.specializationId);
  const roles = character?.categoryId === "rom" ? partyRolesForClass(character.classId)
    : specialization ? [specialization.role] : [];
  const eligibleCharacter = character && ["wow", "rom"].includes(character.categoryId ?? "wow");
  const selectedRole = role && roles.includes(role) ? role : roles[0];
  const busy = ["queued", "preparing", "countdown", "active"].includes(race.status) || race.preparingContent;
  const start = async () => {
    if (!character || !eligibleCharacter || !selectedRole || !allEntries.length) return;
    const latest = await loadDungeonQueuePolicy();
    const candidates = allEntries.filter((entry) => dungeonEnabledForQueue(latest, entry));
    if (!candidates.length) { useDungeonRaceStore.setState({ error: "No dungeon is enabled for this race queue." }); return; }
    if (practice) await race.startPractice(character, selectedRole,
      dungeonId || candidates[Math.floor(Math.random() * candidates.length)].id, tier, source);
    else if (session?.accessToken) await race.startOnline(session, character, selectedRole, pool, dungeonId || undefined);
  };
  return <FrontSurface className="dungeon-race-screen" ariaLabel="Bite-Sized Dungeon Race">
    <header className="dungeon-race-screen__header"><BrandMark compact /><div><small>Main menu / Dungeon Race</small>
      <h1>Bite-Sized Dungeon Race</h1></div><button className="front-button" type="button" onClick={() => { void race.leave(); onClose(); }}>Main menu</button></header>
    <main className="dungeon-race-screen__layout">
      <section className="dungeon-race-screen__setup">
        <p>Race another player or a full NPC party through matching short dungeons. First final boss kill wins. You can still finish and earn its card after a loss. Each race rolls one kill mechanic and one movement mechanic for both sides.</p>
        <div className="dungeon-race-screen__choices" role="group" aria-label="Race type">
          <button className="front-button" type="button" aria-pressed={!practice} disabled={!session?.accessToken || busy} onClick={() => setPractice(false)}>Online ranked</button>
          <button className="front-button" type="button" aria-pressed={practice} disabled={busy} onClick={() => setPractice(true)}>Offline practice</button>
        </div>
        <div className="dungeon-race-screen__choices" role="group" aria-label="Dungeon pool">
          <button className="front-button" type="button" aria-pressed={pool === "authored"} disabled={busy}
            onClick={() => { setPool("authored"); setDungeonId(""); }}>Bite-Sized</button>
          <button className="front-button" type="button" aria-pressed={pool === "randomized"} disabled={busy}
            onClick={() => { setPool("randomized"); setDungeonId(""); }}>Randomized Bite-Sized</button>
        </div>
        <label>{pool === "randomized" ? "Creature pool" : "Dungeon"}<select value={dungeonId} disabled={busy} onChange={(event) => setDungeonId(event.target.value)}>
          <option value="">{pool === "randomized" ? "Random available creature pool" : "Random eligible dungeon"}</option>
          {allEntries.map((entry) => <option key={entry.id} value={entry.id}>{entry.title}</option>)}
        </select></label>
        <div className="dungeon-race-screen__choices" role="group" aria-label="Your role">
          {roles.map((candidate) => <button key={candidate} className="front-button" type="button"
            aria-pressed={selectedRole === candidate} disabled={busy} onClick={() => setRole(candidate)}>{PARTY_ROLE_LABELS[candidate]}</button>)}
        </div>
        {practice && <div className="dungeon-race-screen__practice">
          <label>NPC skill<select value={tier} onChange={(event) => setTier(event.target.value as RaceBotTier)}>
            <option value="novice">Novice</option><option value="regular">Regular</option>
            <option value="veteran">Veteran</option><option value="elite">Elite</option>
          </select></label>
          <label>NPC party<select value={source} onChange={(event) => setSource(event.target.value as RaceBotSource)}>
            <option value="wow">WoW</option><option value="rom">RoM</option>
          </select></label>
          <small>Practice awards local boss cards and never enters a leaderboard.</small>
        </div>}
        {!eligibleCharacter && <p role="status">Select a WoW or RoM character to race. CoA characters will be added later.</p>}
        {!session?.accessToken && !practice && <p role="status">Sign in online for ranked races.</p>}
        {!allEntries.length && <p role="status">No Bite-Sized dungeon is enabled for this queue.</p>}
        {race.status === "queued" && <p role="status">Searching for a player. An NPC team joins after five seconds.</p>}
        {race.status === "preparing" && <p role="status">{race.preparingContent ? "Installing race content…" : "Preparing both parties…"}</p>}
        {race.error && <p role="alert">{race.error}</p>}
        <div className="dungeon-race-screen__choices"><button className="front-button front-button--primary" type="button"
          disabled={busy || !eligibleCharacter || !selectedRole || !allEntries.length} onClick={() => void start()}>
          {practice ? "Start practice" : "Enter race queue"}</button>
          {busy && <button className="front-button" type="button" onClick={() => void race.leave()}>Cancel race</button>}
        </div>
      </section>
      <section className="dungeon-race-screen__board" aria-label="Dungeon Race leaderboards">
        <h2>Leaderboards</h2>
        {boardScope === "dungeon" && boardView === "times" && <BiteSizedBoardFilters selection={spotBoard} />}
        <div className="dungeon-race-screen__choices"><button className="front-button" type="button" aria-pressed={boardScope === "overall"} onClick={() => setBoardScope("overall")}>Overall wins</button>
          <button className="front-button" type="button" aria-pressed={boardScope === "dungeon"} onClick={() => setBoardScope("dungeon")}>This dungeon</button></div>
        {boardScope === "dungeon" && <div className="dungeon-race-screen__choices"><button className="front-button" type="button" aria-pressed={boardView === "wins"} onClick={() => setBoardView("wins")}>Wins &amp; losses</button>
          <button className="front-button" type="button" aria-pressed={boardView === "times"} onClick={() => setBoardView("times")}>Fastest clears</button></div>}
        {boardScope === "dungeon" && bossOptions.length > 1 && <label>Boss<select value={selectedBoardBossId}
          onChange={(event) => setBoardBossId(event.target.value)}>
          {bossOptions.map((boss) => <option key={boss.id} value={boss.id}>{boss.name}</option>)}
        </select></label>}
        <div className="dungeon-race-screen__choices"><button className="front-button" type="button" aria-pressed={period === "30d"} onClick={() => setPeriod("30d")}>Last 30 days</button>
          <button className="front-button" type="button" aria-pressed={period === "all"} onClick={() => setPeriod("all")}>All time</button></div>
        {boardError && <p role="status">{boardError}</p>}
        {!boardError && board?.entries.length === 0 && <p>No results yet.</p>}
        {board?.entries.length ? <table><thead><tr><th>Rank</th><th>Player</th>
          <th>{boardScope === "dungeon" && boardView === "times" ? "Best time" : "Wins"}</th>
          {boardScope === "dungeon" && boardView === "times" && <th>Mechanics</th>}
          {!(boardScope === "dungeon" && boardView === "times") && <th>Losses</th>}</tr></thead><tbody>
          {board.entries.map((entry) => <tr key={entry.accountId}><td>#{entry.rank}</td><td>{entry.username}</td>
            <td>{entry.durationMs !== undefined ? formatDungeonDuration(entry.durationMs) : entry.wins}</td>
            {boardScope === "dungeon" && boardView === "times" && <td>{entry.affixIds?.length
              ? entry.affixIds.map((id) => dungeonRaceAffix(id)?.name ?? id).join(" + ") : "Legacy"}</td>}
            {entry.durationMs === undefined && <td>{entry.losses}</td>}</tr>)}</tbody></table> : null}
      </section>
    </main>
  </FrontSurface>;
}